a. Field of the Invention
The present invention relates to a method for mixing and masticating highly viscous materials.
b. Description of the Prior Art
Hitherto it has been customary in industry to mix and to masticate highly viscous materials, such as for example natural and synthetic rubbers, if desired together with additives such as soot, carbon black, clay, vulcanization starters and the like, in an apparatus suitable for that purpose, such as for example a Banbury mixer, as part of the total treatment.
Said mixing is effected in a mixing apparatus comprising a mixing chamber provided with a pair of rotors, driven by a motor, said rotors rotating in opposite direction, and the wall of the mixing chamber being provided with a cooling coil, providing cooling of the wall during the complete treatment continuously and with even circulation velocity of the coolant, except for starting procedures. The selection of the conditions during mixing and masticating is usually on an empirical basis. A consequence thereof is, that the mixing apparatus is not used in the most effective manner, and thus the quality of the product formed will not be optimal, or alternatively the amount of energy required will be excessive. Also the homogenity and the plasticity of the products thus obtained will often not be constant, which is undesirable, as this may lead to problems during further treatment, as this may result in products with inconstant and occasionally undesirable properties.
According to one method the total energy and the number of revolutions of the rotors are recorded, while simultaneously the temperature of the materials treated is recorded. Though this method allows more quality control of the products obtained by mixing and masticating the materials, this treatment is still largely empirical with all the disadvantages resulting therefrom. As a consequence thereof the mixing will frequently be insufficient whereby the resulting product will be inhomogeneous of insufficiently masticated, or the mixing will be continued for too long a period of time, thus resulting in a needless loss of energy as it does not make use of minimal energy for optimal quality.